Place a large rimmed baking sheet in the oven and preheat to 400°F.
Rub both sides of fish with 1 tablespoon oil; season with ¾ teaspoon pepper and ¼ teaspoon salt.
Combine broccoli rabe, the remaining 1 tablespoon oil and ¼ teaspoon each salt and pepper in a large bowl. Massage the broccoli rabe until evenly coated.
Place the fish and broccoli rabe on the hot baking sheet. Roast until the fish is just cooked through and the broccoli rabe is tender, 8 to 10 minutes.
Meanwhile, mix butter, lemon zest, garlic, capers and parsley in a small bowl.
To serve, toss half the piccata butter with the broccoli rabe and dollop the rest on the fish.
Tips: Swordfish populations have increased to a more sustainable levelchoose handline- or harpoon-caught from the North Atlantic and Eastern Pacific. Swordfish is high in mercury, so it's best to eat it only occasionally. Women who may become pregnant, breast-feeding mothers and young children should avoid swordfish. Halibut is a good alternative.
Serving size: 3 oz. fish & ⅔ cup broccoli rabe each
318 calories;22 g fat(8 g sat); 0 g fiber; 6 g carbohydrates; 24 g protein; 3 mcg folate; 87 mg cholesterol; 1 g sugars; 0 g added sugars; 7,736 IU vitamin A; 108 mg vitamin C; 66 mg calcium; 1 mg iron; 421 mg sodium; 425 mg potassium
Vitamin C (180% daily value), Vitamin A (155% dv)